TEST 



535 



TEST 



appearance of a red zone, and on shaking the whole so- 

 lution turns red. (2 1 Naphthylamin sulfonic acid (naph- 

 thionic acid), I gm ; beta-naphthol, 1 gm.; sodium hy- 

 drate, o. 5 gin : water, 200 c. c. Ten drops of the solution 

 are used. (Merck.) T., R.'s, for Sugar in Urine. 

 To 20 drops of urine in a test-tube add about o. I gm. 

 of pure hydrochlorid of phenylhydrazin, about 0.5 gm. 

 of crystallized sodium acetate, and 2 c.c. of water. 

 Heat until it boils, then add 10 c.c. of a 10 ^ solution 

 of sodium hydrate, inverting the tube 5 or 6 times. Set 

 aside. In the presence of sugar within 5 minutes the 

 whole fluid will take a reddish- violet hue. T., R.'s, 

 for Uric Acid. Para-nitranilin 0.5 gm., water 10 c.c, 

 pure concentrated H 2 S0 4 , 15 drops. Put into a glass 

 flask of 150 c.c. capacity, and heat with agitation until 

 dissolved. Water 20 c.c. is now added, the mixture 

 cooled quickly, 2.5 V, NaNOj solution 10 c.c. is 

 added, and diluted, after 15 minutes, with water 60 

 c.c. The mixture is shaken up repeatedly and filtered. 

 The formation of a blue or green color on adding the 

 reagent and 10^ NaOH solution indicates presence 

 of uric acid. (Merck.) T., Rinnmann's, for 

 Zinc. Zinc oxid moistened with cobalt nitrate so- 

 lution and strongly heated on charcoal yields a green 

 color. T., Ritsert's, for Glycerin. Heat 1 c.c. 

 glycerin to boiling with I c.c. NH 3 then add 3 

 drops 5 % AgN0 3 solution — no change should oc- 

 cur in the liquid within 5 minutes. Test intended 

 to show presence of arsenous acid, as well as of 

 acrolein and formic acid ; recent investigations, how- 

 ever, seem to have proved the test to be fallaci- 

 ous. (Merck.) T., R.'s, for Phenacetin. Boil 

 o. t gm. phenacetin I minute with I c.c. concentrated 

 HC1, then dilute with 10 c.c. water, filter after 

 cooling, and treat filtrate with 3 drops 3^ chromic- 

 acid solution —liquid gradually assumes a ruby-red 

 color. (Merck.) Ritsert's Reaction for Sulphonal. 

 Upon heating sulfon'al with gallic or pyrogallic acid, 

 the odor of mercaptan appears. T., Ritthausen's, 

 for Protein. A violet color develops on dissolving 

 protein in dilute H,S0 4 , adding excess of KOH, and 

 then a few drops saturated solution CuS0 4 . (Merck.) 

 T., Roberts -Stolnikoff's, for Albumin in Urine. 

 Depends on employment of Heller's test (see Illus. 

 Diet.). (Merck.)' T., Robin's, for Alkaloids. 

 Mix 1 part of substance with 2 parts cane-sugar and 

 add I or 2 drops H.,S0 4 , stirring with a glass rod. 

 Alkaloids give colors as follows : Atropin — violet, 

 changing to brown ; cod fin — cherry-red, changing to 

 violet ; morphin — rose, rapidly changing to violet ; 

 narcotin — persistent mahogany color ; quinin — green- 

 ish, bright-yellow, changing to dark coffee color with 

 yellow margin; salicin — bright-red; strychnin, red- 

 dish, changing to dark coffee color ; veratrin — dark 

 green. (Merck.) T., Robinet's, for Morphin. 

 See T., Robiquefs (Illus. Diet.). T., R.'s, for 

 Salicylic Acid in Urine. Precipitate urine with 

 neutral lead acetate, remove excess of lead with dilute 

 H,S0 4 , and at once add Fe,Cl 6 . If liquid has a red 

 color (due to iron acetate) add H,S0 4 until colorless 

 or the purple salicylic-acid color appears. (Merck.) 

 T.. Roger's, for Tin. Ammonium molybdate affords 

 a blue color with stannous chlorid, still visible in solu- 

 tion of 1 : 250,000. (Merck.) T., Roman-Delluc's, 

 for Urobilin in Urine. Shake out 100 c.c. urine 

 with 20 c.c. chloroform, after acidulating with 8 to 10 

 drops acetic acid. Overlay 2 c.c. of clear chloroformic 

 solution with 4 c.c. of 1 : 1000 solution zinc acetate in 

 95 -'r alcohol. At line of separation a characteristic 

 green fluorescence appears if urobilin be present, more 

 easily recognized against a black background. On 

 shaking, fluorescence is more marked, and the mixture 



acquires a pink tint. (Merck.)* Rose's Biuret Re- 

 action for Albumins. Alkalinize the albumin solu- 

 tion with soda lye and add drop by drop, with con- 

 stant shaking, a dilute copper sulfate solution (17 or 

 18 gm. crystallized cupric sulfate in I liter of water . 

 The solution will assume first a rose-red, then a violet, 

 and finally a blue color, which latter appears of a 

 decided reddish tint when compared with a normal 

 alkaline copper solution. T., Rosenbach's Modi- 

 fication of Gmelin's, for Bile Pigments. When 

 the liquid has all been filtered through a very small 

 filter, apply to the inside of the filter a drop of 

 nitric acid containing only a very little nitrous 

 acid, when a pale yellow spot will form, sunounded 

 by colored rings, which are yellow-red, violet, blue, 

 and green. Rosenstiel's Anilin Reaction. See 

 T., Rung?* (Illus. Diet.). T., Rosin's, for Indigo 

 Red. Render the liquid alkaline with sodium car- 

 bonate and extract with ether, which is colored red 

 by the indigo red. T., Rossbach's, for Poison- 

 ous Alkaloids. Action of alkaloids upon infusoria 

 is tested, and the degree of toxicity estimated from 

 intensity of action. (Merck.) Roussin's Crystals. 

 Nicotin in ethereal solution yields with an ethereal 

 iodin solution an oily mass, from which ruby colored 

 crystals, reflecting dark blue, gradually separate. 

 T., Royere's, De la, for Fixed Oils. A red color 

 develops on treating a few drops of oil with 2 drops 

 fuchsin solution to which just enough alkali has been 

 added to decolorize it. The color is produced by the 

 free acids in the oils, and according to Halphen the 

 value of the test is limited by the fact that mineral 

 oils may also contain acids. The acids in oils used as 

 lubricators may also be neutralized by alkaline soaps, 

 though the presence of the latter can be easily de- 

 tected by the red color formed on adding a solution of 

 congo red just colored violet by HO. ( Merck. ) T. t 

 Rubner's, for Carbon Monoxid in Blood. Agi- 

 tate the blood with 4 or 5 volumes of solution of lead 

 acetate for one minute. If the blood contains CO, it 

 will retain its bright color; if it does not, it will turn 

 chocolate-brown. T., R.'s, for Glucose. Add to 

 the liquid an excess of lead acetate ; filter, and add to 

 the filtrate ammonium hydrate until no further precipi- 

 tate is produced. Wann gently, when the precipitate 

 formed will gradually become pink ; this color de- 

 creases on standing. T., Rudolf- Fischer's, for 

 Acetanilid. Heat 5 g™- acetanilid for some time 

 with 5 gm. dry ZnClj — a yellow coloring-matter with 

 moss-green fluorescence forms, which may be dissolved 

 by heating with very dilute HC1. Product formed is 

 flavanilin, C 16 H U X,. (Merck.) T., Rupeau's, for 

 Picric Acid in Beer. Ferrous sulfate, 5 gm. tartaric 

 acid, 5 gm., water, 200 gm. Mix solution with an equal 

 volume of saturated solution NaCl. Overlay I to 2 c.c. 

 reagent on 0.5 c.c. beer and add 2 drops NH S . Pres- 

 ence of picric acid is shown by a red color. (Merck, t 

 T., Sabatier's, for Copper. Add I drop solution of 

 a copper salt to I c.c. concentrated HBr — if much cop- 

 per is present, a purple-red color at once develops ; if 

 little, color is lilac. A o.oooi r c solution of a copper 

 salt still gives the reaction. A mixture of KI and 

 H 3 P0 4 also gives the reaction, which develops on first 

 carefully warming, then cooling. (Merck.) T., S.'s, 

 for Nitrites. On dissolving a few fragments cuprous 

 oxid in concentrated H,S0 4 , containing a little nitrite, 

 the solution is colored intensely violet to purple. All 

 cuprous compounds, and cuproso-cupric derivatives 

 afford the color. Cupric compounds do not react. 

 1 Merck.) T., Sabatin's, for Copper. Trace of a 

 copper salt dissolved in concentrated hydrobromic acid 

 develops an intense purple color. One drop of a 



